Abrasive belt grinding device



DB3; 1947- J. I. CARLSSON I ,427

ABRASIVE BELT GRINDING DEVICE Filed June 27, 1945 Patented Dec. 30, 1947 ABRASIVE BELT GRINDING DEVICE John Ivar Carlsson, Sundbyberg, Sweden, assignor to Rolling Fabriksaktlebolag, Stockholm, Sweden, a corporation of Sweden Application June 27, 1945, Serial No. 601,867 In Sweden February 22, 1943 1 Claim. l

ing irregular surfaces. A further object is to pro- I vide a device by means of which articles can be manually treated within a short period of time.

These and further objects I attain by mechanism illustrated in the accompanying drawings, in which:

Fig. 1 is a side elevation of a grinding machine provided with a device according to the invention; Fig. 2 is a plan view of Figure 1.

Referring to the drawing, the table M of the grinding machine rests on a stand 22 and carries an electric motor l to the shaft of which there is secured a driving pulley t. The periphery of the said pulley may be plane or preferably convex or even concave in cross-section. An endless belt l8 provided with a coating of emery or other suitable grinding or polishing material runs over the pulley t and a tension pulley 5 which is rotatably mounted on a pin 20. Said pin 20 is secured to one arm of a double-armed lever 9 the other arm of which carries a counterweight it which may be adjustable. The lever 9 is pivotally mounted at the upper portion of a support t which near its lower end is in turn pivotally mounted on a, horizontal pin provided in a support I. By means of a set screw MI and in nut ti or similar device, the support 8 can be locked in any desired inclined position relative to the horizontal plane. v

If the support 8 is swung about its pivot, the tension pulley b will be moved such that the belt in can be given any desired inclination towards the right or left as viewed in Fig. 1 so as to become readily accessible in grinding of works of difierent kinds. The support 6 is advantageously bent outwards from the table 2"! so as not to interfere with certain kinds of works. By suitable arrangement of the pivots of the support 8 relative to the axes of the pulleys 3 and B, the grind- 2. ing device may be adjusted such that the grinding belt will be horizontal or nearly horizontal. Stop members H and I2 may be provided for limiting the downward swinging movement of the lever 9 and the support 8, respectively.

By means of the grinding machine described, difierent grinding operations may be carried out such as grinding of bowl-shaped or concave surfaces, for instance surfaces of spoons, convex articles, for instance handles, eyes or bent tubes, and plane or faceted bodies. A further advantage consists in that the usual grinding discs are dispensed with and exchanged for belts which provide a many times larger grinding surface and which can be replaced in a very simple manner. As a. result thereof, time-wasting applying of grinding discs is eliminated, and much material is saved. Exchange of belts can be effected even during operation of the machine and thus requires very little time, Due to the variou applications rendered possible by the machine, many articles which hitherto have been treated by timewasting filing, reaming or similar manual treatment, can be finally shaped by grinding.

According to the embodiment illustrated, an arm 31 is pivotally mounted on the shaft to of the tension pulley 5. At the outer end of the arm at, there is mounted a pulley 38 for elongated portions it of the belt it. On the arm 37, there is also mounted a guide pulley 39 located in a manner such that the belt portion it will run close to each other. By means of the pulley it, the grinding belt can be introduced into cavities r of works in order to grind or polish the walls and bottom of such cavities. Means may be provided to lock the arm 8'! in any desired angularposition relative to the lever 9,

- What I claim is:

A grinding device comprising a fixed bearing, a shaft mounted in said bearing, means for driving said shaft, a driving pulley on said shaft, a second fixed bearing, a-support pivotally mounted in said second bearing and adapted to be swung in a vertical plane and to be locked in desired position, a lever pivotally mounted on said support; a guide and tension pulley mounted on said lever, an endless grinding .belt running over said pulleys, an arm pivotally connected with said lever. a third pulley mounted near the end of said arm, a fourth pulley mounted on said Arm. sold belt running from said tension pulley over sold third pulley and over sold fourth pulley to said driving pulley, sald iom-ih pulley beln: lo- Number csted substantially between said tension pulley 462,185 and said thlrd pulley, and an external load on said 5 894,851 lever tor stretching said belt. 933,305 1,669,094 JOHN IVAR CARLSSON. 1,675,183 1,881,162 REFERENCES CITED 1o The following references are of record in the Number me of this patent: 5,713

, mime!) s'rA'rEs PATENTS Name Date Wilson et a1. Oct. 27, 1891 Oakley Aug. 4, 1908 Jackoboioe et a1. Sept. 7, 1909 Landquist May 8. 192a Loefller June 28, 1928 Aurorl et a1. Oct. 4, 1932 FOREIGN. PATENTS Country Date Great Britain Mar. 16, 1899 

